diff --git a/DESCRIPTION b/DESCRIPTION
index 82eb1a3..6992f53 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -11,11 +11,11 @@ Authors@R:
       person("Tom", "Stewart", role = "cph", email = "tom.stewart@aut.ac.nz",
            comment = "holds copyright over original palmsplusr code"))
 License: LGPL-3 | file LICENSE
-Imports: dplyr, sf, readr, tidyr, stringr, palmsplusr, data.table, rlang, purrr, geosphere
+Imports: dplyr, sf, readr, tidyr, stringr, palmsplusr, data.table, rlang, purrr, geosphere, lwgeom
 Remotes: vincentvanhees/palmsplusr
 LazyData: true
 Suggests: testthat, covr, rmarkdown
 Depends: stats, utils, R (>= 3.5.0)
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.3.1
+RoxygenNote: 7.3.2
diff --git a/R/build_whenwhatwhere.R b/R/build_whenwhatwhere.R
index b6c2fb3..d04276e 100644
--- a/R/build_whenwhatwhere.R
+++ b/R/build_whenwhatwhere.R
@@ -30,6 +30,10 @@ build_whenwhatwhere <- function(data = NULL, verbose = TRUE, whenwhat_field = NU
   Nlocations = length(loca)
   for (i in 1:Nlocations) {
     for (j in 1:2) {
+      if (is.na(st_crs(loca[[i]][[j]]))) {
+        stop(paste0("GIS file lacks coordinate reference system specification",
+                    " as expected by hbGIS"), call. = FALSE)
+      }
       txt = paste0(names(loca[[i]])[j], " = loca[[i]][[j]]")
       eval(parse(text = txt))
     }
diff --git a/R/hbGIS.R b/R/hbGIS.R
index f4fc82c..ab7fec7 100644
--- a/R/hbGIS.R
+++ b/R/hbGIS.R
@@ -422,7 +422,6 @@ hbGIS <- function(gisdir = "",
   if (verbose) cat("\n<<< building whenwhatwhere...\n")
   if (length(palms) > 0 & length(whenwhat_field) &
       all(Nlocation_objects > 0) & length(participant_basis) > 0) {
-    
     whenwhatwhere <- build_whenwhatwhere(data = palms, 
                              whenwhat_field = whenwhat_field,
                              loca = loca,